Power line communication involves sending electric data signals through electrically conductive power cables together with electric power signals. Networks for distributing electric power signals constitute the largest deployed networks in the world. Such networks can be used for electric data signal transmission. Numerous protocols have been developed into standards governing transmission of electric data signals through power lines. The coupling of these electric data signals to and from electrically conductive power cables safely and in compliance with government regulations while maintaining low signal loss is key to the successful deployment of these power line communications systems.
U.S. Pat. No. 7,145,440, for example, discloses a broadband coupler capable of direct electrical connection to an energised power line. The coupler includes a conductive portion movable by an adjustable member from a non-conducting retracted position spaced apart from the power transmission line to a forward conducting position in electrical contact with the power line. An insulated arm supports the coupler on the power line. A base on the coupler is engageable with a remotely activated tool in order to accomplish the electrical connection in a safe and secure manner.
In U.S. Pat. No. 7,145,440, broadband data signals are sent to and from customer premises along the shared energized power lines. New coupler connections to the energized power lines allow the additional broadband customers and/or repeaters to join the communication system. Also couplers taught by U.S. Pat. No. 7,145,440 may provide connections to control electronics, routers, wireless transceivers, and may allow the broadband signals to bypass transformers on the power lines.
To minimise signal loss this coupling normally takes place directly on high power cables these being the core electricity conductors within an electrical network thus requiring bulky high current rupturing fuses and fuse holders and a direct physical connection to the electrical system with no way to easily determine or maintain the efficiency of this physical connection for the disproportionately small power line communications signals compared to the electrical power.
It is generally desirable to overcome or ameliorate one or more of the above mentioned difficulties, or at least provide a useful alternative.